This invention relates to methods and arrangements for plasma etching aluminum films carried on a solid substrate.
Many semiconductor processing techniques involve the deposition of a metal, typically aluminum, film on the semiconductor surface followed by an etching process which selectively removes the metal so as to form an electrode or conductor pattern. This etching process is normally effected by masking the metal film with a photoresist material and then immersing the masked workpiece in a liquid etch. Although widely employed, such etch processes suffer from the disadvantage that gas bubbles formed on the metal surface during the etching process cause local inhibition of etching. Also liquid etches tend to undercut the metal film thus reducing the conductor track cross section.